DETERMINATION OF MARK HOUWINK CONSTANTS AND STUDY ON MOLECULAR WEIGHTS AND MOLECULAR WEIGHT DISTRIBUTION OF POLY( p DIETHYNYLBENZENE)

The Mark Houwink constants of poly ( p diethynylbenzene) (PDEB) in THF at 25℃ were determined from GPC and intrinsic viscosity η of broad distribution samples based on the principle of GPC universal calibration and Weiss method,and the values of K =7 62×10 -3 and α =0 26 were obtained.The obtained K and α values were reliable and could be used for calculating the molecular weights of PDEB within the relative error of 6%,which was proved by η error checking and VPO analysis.The effects of monomer concentration,polymerization temperature,polymerization time on molecular weights and molecular weight distribution of PDEB were studied with GPC.The crosslinking,grafting,and chain transferring to monomer may exist in the polymerization of p diethynylbenzene.